The 21-year-old was a superstar cornerback at Ohio State University and draft experts say he could be taken as high as #10 in the draft on Thursday.

But according to a police report filed in Cleveland, and obtained by TMZ Sports, a 23-year-old white female told police Conley violated her in a hotel suite bathroom at a Westin hotel on April 9.

According to the report, the accuser says she met Conley in a hotel elevator around 3AM and brought her back to his hotel room. She claims Conley asked her to have a foursome with another friend of his and a woman. The accuser says she declined and offered to watch the other couple have sex in the hotel room bathroom instead.

A short time later, the woman says Conley unbuttoned her pants and began to have sex with her. She claims she said, "No, stop, it hurts!" but he kept going until he finished. She says Conley then kicked her out of the hotel room.

The woman called 911 and described her assailant as a "black male who wouldn't take his sunglasses off and had an Ohio State tattoo on his left forearm."

The woman says she went to a local hospital where a rape kit was administered.

An officer tried to speak with the accuser at the hospital but she refused to do an interview. Instead, she told the cop she wanted to go home and "that her dignity was stripped from her in a matter of minutes." She refused to speak to cops after that.

As for Conley, two of his friends who were in the hotel room were interviewed by police and told cops Conley never hooked up with the woman and that she was just mad that she got kicked out of the room.

One of Conley's friends said the two had been lying on the bed together "but nothing happened."

Conley was not in the room when police arrived and his friends said they did not know where he went.

Conley's attorney spoke with Cleveland19 and denied the allegations calling the accusations "ludicrous and ridiculous."

Cops are investigating but so far no arrests have been made and no charges have been filed.

We spoke with police who tell us the results from the rape kit are not in at this point. The sex crimes unit is now on the case.

10:49 AM PT -- Conley is now tweeting about the case ... kinda.

Conley's college teammate, Marshon Lattimore (who's also an NFL Draft prospect), posted, "So the first thing you say to a girl that you meet in the elevator is let's have a foursome? Lol that doesn't even make sense."

He added, "It's crazy how these females are nowadays, they most definitely prey on you and try to ruin you."

Conley retweeted the post and commented, "Lord knows!"

Marshon added, "We good over here though bro [Gareon Conley] we know the deal!"